Using various techniques of RNA/DNA hybridization, this project will continue to define the key alterations of RNA regulation which are common to the different stages of carcinogenesis by chemicals, viruses, radiation and synthetic hormone. The alteration in transport of RNA from the nucleus to the cytoplasm which is characteristic of chemical carcinogens in their target tissues and is irreversible in that system will be studied further after irradiation or hormone stimulation with emphasis on determining the reversibility of the alteration in these systems. Studies will be continued on the size and location of the RNAs abnormally transported to the cytoplasm after cancer initiation, and on their further processing or translocation during the promotion period of carcinogenesis.